EUVD-2026-21907
GHSA-5gm9-622f-qcg5
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
7DescriptionCVE.org
LibreNMS versions before 26.3.0 are affected by an authenticated Cross-site Scripting vulnerability on the showconfig page. Successful exploitation requires administrative privileges. Exploitation could result in XSS attacks being performed against other users with access to the page.
AnalysisAI
Cross-site Scripting (XSS) in LibreNMS versions before 26.3.0 allows authenticated administrators to inject malicious scripts on the showconfig page, enabling attacks against other authorized users. The vulnerability requires high administrative privileges and user interaction (clicking a malicious link) to execute, resulting in integrity impact to other users' sessions. Publicly available exploit code exists, though CISA KEV status is not confirmed.
Technical ContextAI
This is a Stored or Reflected XSS vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation) in LibreNMS, a network monitoring and management platform. The showconfig page fails to properly sanitize or encode user-supplied input before rendering it in HTML context. Because LibreNMS is built as a PHP-based web application, insufficient output encoding allows an attacker with admin credentials to inject JavaScript that executes in victims' browsers. The attack surface is limited to the showconfig page specifically, and exploitation requires the victim to access a crafted URL or interact with the compromised page while logged in.
RemediationAI
Upgrade LibreNMS to version 26.3.0 or later, which includes the fix for XSS on the showconfig page. Administrators should prioritize this update in their patching cycle, particularly for instances exposed to untrusted networks or with multiple administrative accounts. In the interim, restrict administrative console access to trusted networks via firewall rules and monitor admin activity for suspicious behavior. Refer to the ProjectBlack security advisory at https://projectblack.io/blog/librenms-authenticated-rce-and-xss/#xss-on-showconfig-page-2630 for additional context and verification of patched versions.
An issue was discovered in LibreNMS through 1.47. Rated high severity (CVSS 7.2), this vulnerability is remotely exploit
Librenms 21.11.0 is affected by a path manipulation vulnerability in includes/html/pages/device/showconfig.inc.php. Rate
An issue was discovered in LibreNMS through 1.47. Rated critical severity (CVSS 9.8), this vulnerability is remotely exp
SQL injection in LibreNMS 25.12.0 and below. PoC and patch available.
An issue was discovered in LibreNMS through 1.47. Rated critical severity (CVSS 9.1), this vulnerability is remotely exp
SQL injection in LibreNMS versions 25.12.0 and below allows authenticated users to extract sensitive database informatio
LibreNMS is an open-source, PHP/MySQL/SNMP-based network monitoring system. Rated high severity (CVSS 8.8), this vulnera
An issue was discovered in LibreNMS before 1.65.1. Rated high severity (CVSS 8.8), this vulnerability is remotely exploi
An issue was discovered in LibreNMS 1.50.1. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable,
An issue was discovered in LibreNMS through 1.47. Rated high severity (CVSS 8.8), this vulnerability is remotely exploit
Remote code execution in LibreNMS network monitoring platform (versions prior to 26.3.0) allows authenticated administra
An issue was discovered in LibreNMS 1.50.1. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable,
Same weakness CWE-79 – Cross-site Scripting (XSS)
View allShare
External POC / Exploit Code
Leaving vuln.today